filter hooks by connection and context in core

(cherry picked from commit 9126ce9202)

docs/plugin-api-additions/compatibility.md

@@ -0,0 +1,24 @@
+# Optional plugin API additions (discussion #144)
+
+Existing hooks, callbacks, return values, context lookup, strings and menu behaviour
+remain unchanged. The C plugin function table gains four fixed append-only slots;
+unused slots are NULL. Older binaries use the unchanged prefix. A plugin must check
+the documented get_info() feature key before accessing a new slot on an older host.
+New Python modules are installed by Meson and the existing Windows copy/installer
+pipeline. Only modules present in the installation are exported; imports of
+zoitechat, hexchat and xchat retain their compatibility aliases.
+
+All APIs run on the client main thread unless explicitly documented otherwise.
+New reserved flags must be zero. These changes do not make old API calls thread-safe.
+
+Nested hook dispatch defers deleted-hook reclamation until its outermost return,
+so new observers can safely emit events and unhook themselves or other hooks.
+
+The optional asyncio module requires Python 3.7 or newer; older supported
+interpreters skip that module and retain the existing scripting API.
+
+Python reload drops the script/API modules while retaining the embedding module
+so callback and lib.ph pointer types keep the same CFFI identity.
+
+Server-hook insertion matches both raw and attrs hooks so documented priorities
+are honoured for mixed registrations, including new filtered attrs callbacks.

docs/plugin-api-additions/filters.md

@@ -0,0 +1,24 @@
+# Core-filtered hooks
+
+Python: `hook_server_filtered(name, callback, userdata=None, priority=PRI_NORM,
+connection_id=None, channel=None)` and `hook_print_filtered(...)`.
+Callbacks match the existing attrs variants: `(word, word_eol, userdata, attrs)`.
+The connection ID distinguishes duplicate names; None/-1 means any connection
+(including connection ID zero). A channel restriction uses that connection's
+IRC comparator. None means any context; an empty string is an exact restriction.
+
+C: the corresponding zoitechat_hook_*_filtered functions accept
+`(ph, name, pri, flags, connection_id, channel, callback, userdata)`;
+flags=0, ID=-1 for any and NULL channel for any. Check
+`get_info("api_context_filters")` for "1" before accessing the new Windows slots.
+
+Filtering takes place before Python/interpreter entry. Existing unrestricted
+hooks, priority, EAT semantics and unload/unhook handling are unchanged.
+Filters refer to the core-selected context, not an IRC target parsed from the
+line: unknown queries/channels can still have a server-tab context, and QUIT
+has its usual single server-hook context. Connection IDs last only this process.
+
+```python
+zoitechat.hook_print_filtered('Channel Message', callback,
+                             connection_id=zoitechat.get_prefs('id'), channel='#zoitechat')
+```

plugins/python/_zoitechat.py

@@ -383,3 +383,24 @@ def find_context(server=None, channel=None):
         return None
 
     return Context(ctx)
+
+
+# Optional additive APIs live in separate modules so builds can select features.
+def __load_additive_features():
+    import importlib
+    import os
+
+    for suffix in ('fd', 'events', 'async', 'names', 'contexts',
+                   'post', 'filters', 'caps'):
+        if suffix == 'async' and sys.version_info < (3, 7):
+            continue
+        name = '_zoitechat_' + suffix
+        if not os.path.isfile(os.path.join(os.path.dirname(__file__), name + '.py')):
+            continue
+        module = importlib.import_module(name)
+        for symbol in module.__all__:
+            globals()[symbol] = getattr(module, symbol)
+            __all__.append(symbol)
+
+
+__load_additive_features()

plugins/python/_zoitechat_filters.py

@@ -0,0 +1,36 @@
+"""Context restrictions evaluated by core before entering Python."""
+import operator
+import _zoitechat as api
+from _zoitechat_embedded import ffi, lib
+
+__all__ = ['hook_server_filtered', 'hook_print_filtered']
+
+
+def _register(name, callback, userdata, priority, connection_id, channel, server):
+    if not callable(callback):
+        raise TypeError('callback must be callable')
+    connection_id = -1 if connection_id is None else operator.index(connection_id)
+    if connection_id < -1 or connection_id > 2147483647:
+        raise ValueError('connection_id must fit the C API; -1 means any')
+    plugin = api.__get_current_plugin()
+    hook = plugin.add_hook(callback, userdata)
+    register = lib.zoitechat_hook_server_filtered if server else lib.zoitechat_hook_print_filtered
+    dispatch = lib._on_server_attrs_hook if server else lib._on_print_attrs_hook
+    handle = register(lib.ph, name.encode(), priority, 0, connection_id,
+                      ffi.NULL if channel is None else channel.encode(), dispatch, hook.handle)
+    if handle == ffi.NULL:
+        hook.is_unload = True
+        plugin.remove_hook(id(hook))
+        raise RuntimeError('unable to install filtered hook')
+    hook.zoitechat_hook = handle
+    return id(hook)
+
+
+def hook_server_filtered(name, callback, userdata=None, priority=api.PRI_NORM,
+                         connection_id=None, channel=None):
+    return _register(name, callback, userdata, priority, connection_id, channel, True)
+
+
+def hook_print_filtered(name, callback, userdata=None, priority=api.PRI_NORM,
+                        connection_id=None, channel=None):
+    return _register(name, callback, userdata, priority, connection_id, channel, False)

plugins/python/meson.build

@@ -27,7 +27,11 @@ python3_source = custom_target('python-bindings',
   command: [find_program('generate_plugin.py'), '@INPUT@', '@OUTPUT@']
 )
 
-install_data(['_zoitechat.py', 'zoitechat.py', 'xchat.py', 'hexchat.py'],
+# Include any selected additive API modules alongside the compatibility modules.
+python_api_files = run_command(python3, '-c',
+  'import glob,sys; print("\\n".join(sorted(glob.glob(sys.argv[1] + "/_zoitechat*.py"))))',
+  meson.current_source_dir(), check: true).stdout().strip().split('\n')
+install_data(python_api_files + ['zoitechat.py', 'xchat.py', 'hexchat.py'],
   install_dir: join_paths(get_option('libdir'), 'zoitechat/python')
 )
 

plugins/python/python.py

@@ -590,7 +590,12 @@ def _on_plugin_deinit():
     sys.stderr = sys.__stderr__
     pydoc.help = pydoc.Helper()
 
-    for mod in ('_zoitechat', 'zoitechat', 'xchat', '_zoitechat_embedded'):
+    # CFFI callbacks keep the embedding module's ffi/lib identity for the
+    # process lifetime; deleting it creates incompatible types on reload.
+    for mod in ('_zoitechat', 'zoitechat', 'hexchat', 'xchat',
+                '_zoitechat_fd', '_zoitechat_events', '_zoitechat_async',
+                '_zoitechat_names', '_zoitechat_contexts', '_zoitechat_post',
+                '_zoitechat_filters', '_zoitechat_caps'):
         try:
             del sys.modules[mod]
 

plugins/python/python3.vcxproj

@@ -52,6 +52,7 @@
     <None Include="xchat.py" />
     <None Include="hexchat.py" />
     <None Include="_zoitechat.py" />
+    <None Include="_zoitechat_*.py" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(IntDir)python.c" />

plugins/python/python38.vcxproj

@@ -52,6 +52,7 @@
     <None Include="xchat.py" />
     <None Include="hexchat.py" />
     <None Include="_zoitechat.py" />
+    <None Include="_zoitechat_*.py" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(IntDir)python.c" />

src/common/plugin.c

@@ -99,6 +99,9 @@ struct _zoitechat_hook
 	int tag;				/* for timers & FDs only */
 	int type;			/* HOOK_* */
 	int pri;	/* fd */	/* priority / fd for HOOK_FD only */
+	int connection_filter;
+	char *channel_filter;
+	gboolean context_filtered;
 };
 
 struct _zoitechat_list
@@ -176,6 +179,7 @@ enum
 
 GSList *plugin_list = NULL;	/* export for plugingui.c */
 static GSList *hook_list = NULL;
+static unsigned int plugin_dispatch_depth;
 
 extern const struct prefs vars[];	/* cfgfiles.c */
 
@@ -243,7 +247,7 @@ plugin_list_add (zoitechat_context *ctx, char *filename, const char *name,
 {
 	zoitechat_plugin *pl;
 
-	pl = g_new (zoitechat_plugin, 1);
+	pl = g_new0 (zoitechat_plugin, 1);
 	pl->handle = handle;
 	pl->filename = filename;
 	pl->context = ctx;
@@ -350,6 +354,8 @@ plugin_add (session *sess, char *filename, void *handle, void *init_func,
 		pl->zoitechat_emit_print_attrs = zoitechat_emit_print_attrs;
 		pl->zoitechat_event_attrs_create = zoitechat_event_attrs_create;
 		pl->zoitechat_event_attrs_free = zoitechat_event_attrs_free;
+		pl->zoitechat_hook_server_filtered = zoitechat_hook_server_filtered;
+		pl->zoitechat_hook_print_filtered = zoitechat_hook_print_filtered;
 
 		/* run zoitechat_plugin_init, if it returns 0, close the plugin */
 		if (((zoitechat_init_func *)init_func) (pl, &pl->name, &pl->desc, &pl->version, arg) == 0)
@@ -610,6 +616,7 @@ plugin_hook_run (session *sess, char *name, char *word[], char *word_eol[],
 	zoitechat_hook *hook;
 	int ret, eat = 0;
 
+	plugin_dispatch_depth++;
 	list = hook_list;
 	while (1)
 	{
@@ -619,6 +626,15 @@ plugin_hook_run (session *sess, char *name, char *word[], char *word_eol[],
 
 		hook = list->data;
 		next = list->next;
+		if (hook->context_filtered &&
+			(!is_session (sess) ||
+			 (hook->connection_filter != -1 && hook->connection_filter != sess->server->id) ||
+			 (hook->channel_filter && sess->server->p_cmp (hook->channel_filter, sess->channel))))
+		{
+			list = next;
+			continue; /* filter in C before entering an interpreter */
+		}
+
 		hook->pl->context = sess;
 
 		/* run the plugin's callback function */
@@ -655,6 +671,10 @@ plugin_hook_run (session *sess, char *name, char *word[], char *word_eol[],
 	}
 
 xit:
+	/* Nested callbacks can unhook entries still used by an outer dispatch.
+	 * Keep both hook objects and list links alive until the outermost return. */
+	if (--plugin_dispatch_depth != 0)
+		return eat;
 	/* really remove deleted hooks now */
 	list = hook_list;
 	while (list)
@@ -806,7 +826,7 @@ plugin_insert_hook (zoitechat_hook *new_hook)
 			break;
 		case HOOK_SERVER:
 		case HOOK_SERVER_ATTRS:
-			new_hook_type = HOOK_SERVER | HOOK_PRINT_ATTRS;
+			new_hook_type = HOOK_SERVER | HOOK_SERVER_ATTRS;
 			break;
 		default:
 			new_hook_type = new_hook->type;
@@ -1018,10 +1038,45 @@ zoitechat_unhook (zoitechat_plugin *ph, zoitechat_hook *hook)
 
 	g_free (hook->name);	/* NULL for timers & fds */
 	g_free (hook->help_text);	/* NULL for non-commands */
+	g_free (hook->channel_filter);
+	hook->channel_filter = NULL;
 
 	return hook->userdata;
 }
 
+static zoitechat_hook *
+plugin_add_filtered_hook (zoitechat_plugin *ph, const char *name, int pri,
+                         int flags, int connection_id, const char *channel,
+                         int type, void *callback, void *userdata)
+{
+    zoitechat_hook *hook;
+    if (flags != 0 || connection_id < -1 || !name || !callback)
+        return NULL;
+    hook = plugin_add_hook (ph, type, pri, name, NULL, callback, 0, userdata);
+    hook->context_filtered = TRUE;
+    hook->connection_filter = connection_id;
+    hook->channel_filter = g_strdup (channel);
+    return hook;
+}
+
+zoitechat_hook *
+zoitechat_hook_server_filtered (zoitechat_plugin *ph, const char *name, int pri,
+                               int flags, int connection_id, const char *channel,
+                               zoitechat_serv_attrs_cb *callback, void *userdata)
+{
+    return plugin_add_filtered_hook (ph, name, pri, flags, connection_id, channel,
+        HOOK_SERVER_ATTRS, callback, userdata);
+}
+
+zoitechat_hook *
+zoitechat_hook_print_filtered (zoitechat_plugin *ph, const char *name, int pri,
+                              int flags, int connection_id, const char *channel,
+                              zoitechat_print_attrs_cb *callback, void *userdata)
+{
+    return plugin_add_filtered_hook (ph, name, pri, flags, connection_id, channel,
+        HOOK_PRINT_ATTRS, callback, userdata);
+}
+
 zoitechat_hook *
 zoitechat_hook_command (zoitechat_plugin *ph, const char *name, int pri,
 						  zoitechat_cmd_cb *callb, const char *help_text, void *userdata)
@@ -1181,6 +1236,9 @@ zoitechat_get_info (zoitechat_plugin *ph, const char *id)
 		return text_find_format_string (e);
 	}
 
+	if (strcmp (id, "api_context_filters") == 0)
+		return "1";
+
 	hash = str_hash (id);
 	/* do the session independant ones first */
 	switch (hash)

src/common/plugin.h

@@ -150,6 +150,15 @@ struct _zoitechat_plugin
 	void (*zoitechat_event_attrs_free) (zoitechat_plugin *ph,
 									  zoitechat_event_attrs *attrs);
 
+	/* Additive API slots: append only; old binary offsets are unchanged. */
+	zoitechat_hook *(*zoitechat_hook_print_after) (zoitechat_plugin *, const char *, int,
+		int, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_server_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_print_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_register_capability) (zoitechat_plugin *, const char *, int, int, void *);
+
 	/* PRIVATE FIELDS! */
 	void *handle;		/* from dlopen */
 	char *filename;	/* loaded from */

src/common/zoitechat-plugin.h

@@ -193,10 +193,31 @@ struct _zoitechat_plugin
 	zoitechat_event_attrs *(*zoitechat_event_attrs_create) (zoitechat_plugin *ph);
 	void (*zoitechat_event_attrs_free) (zoitechat_plugin *ph,
 									  zoitechat_event_attrs *attrs);
+	/* Additive API slots: append only; old binary offsets are unchanged. */
+	zoitechat_hook *(*zoitechat_hook_print_after) (zoitechat_plugin *, const char *, int,
+		int, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_server_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_print_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_register_capability) (zoitechat_plugin *, const char *, int, int, void *);
+
 };
 #endif
 
 
+/* api_context_filters=1: connection_id -1 is any; NULL channel is any. */
+zoitechat_hook *zoitechat_hook_server_filtered (zoitechat_plugin *ph,
+    const char *name, int pri, int flags, int connection_id, const char *channel,
+    int (*callback) (char *word[], char *word_eol[],
+                     zoitechat_event_attrs *attrs, void *userdata),
+    void *userdata);
+
+zoitechat_hook *zoitechat_hook_print_filtered (zoitechat_plugin *ph,
+    const char *name, int pri, int flags, int connection_id, const char *channel,
+    int (*callback) (char *word[], zoitechat_event_attrs *attrs, void *userdata),
+    void *userdata);
+
 zoitechat_hook *
 zoitechat_hook_command (zoitechat_plugin *ph,
 		    const char *name,
@@ -416,6 +437,8 @@ zoitechat_pluginpref_list (zoitechat_plugin *ph,
 #define zoitechat_hook_server ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_server)
 #define zoitechat_hook_server_attrs ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_server_attrs)
 #define zoitechat_hook_print ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_print)
+#define zoitechat_hook_server_filtered ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_server_filtered)
+#define zoitechat_hook_print_filtered ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_print_filtered)
 #define zoitechat_hook_print_attrs ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_print_attrs)
 #define zoitechat_hook_timer ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_timer)
 #define zoitechat_hook_fd ((ZOITECHAT_PLUGIN_HANDLE)->zoitechat_hook_fd)

win32/copy/copy.vcxproj

@@ -90,6 +90,7 @@
       <MSWindowsTheme Include="$(DepsRoot)\share\themes\MS-Windows\**\*" />
       <HicolorIcons Include="$(DepsRoot)\share\icons\hicolor\index.theme" />
       <HicolorIcons Include="$(DepsRoot)\share\icons\hicolor\**\*.*" />
+      <PythonAdditiveApis Include="..\..\plugins\python\_zoitechat_*.py" />
     </ItemGroup>
 
     <Copy SourceFiles="@(None)" DestinationFolder="$(ZoiteChatRel)" />
@@ -115,6 +116,7 @@
     <Copy SourceFiles="..\..\plugins\python\hexchat.py" DestinationFolder="$(ZoiteChatRel)\python" Condition="'$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true'" />
     <Copy SourceFiles="..\..\plugins\python\zoitechat.py" DestinationFolder="$(ZoiteChatRel)\python" Condition="'$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true'" />
     <Copy SourceFiles="..\..\plugins\python\_zoitechat.py" DestinationFolder="$(ZoiteChatRel)\python" Condition="'$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true'" />
+    <Copy SourceFiles="@(PythonAdditiveApis)" DestinationFolder="$(ZoiteChatRel)\python" Condition="('$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true') and '@(PythonAdditiveApis)' != ''" />
 
     <WriteLinesToFile File="$(ZoiteChatRel)portable-mode" Lines="2" Overwrite="true" />